print at 0.1 - 0.2mm layers (I printed everything at 0.15mm)
3-4 perimeters
30% infill
no supports needed * Grip: You can either print "grip_full.stl" vertically (will require minimal supports) or print the two grip halves ("grip_1.stl" & "grip_2.stl") and put them together with the dowels and some glue.
BOM (Bill of Materials):

Any glue that fits your chosen material (Superglue and/or 5-minute epoxy for PLA; Acetone for ABS)
4x short countersunk M4 screws for the handle (decorative purpose only). Alternatively you could use tape or straps of cloth for a more post-apocalyptic look.
spray paint, acrylic/oil paints, etc.